101 lines
2.9 KiB
Python
101 lines
2.9 KiB
Python
import databases
|
|
import sqlalchemy
|
|
|
|
import ormar
|
|
from tests.settings import DATABASE_URL
|
|
|
|
database = databases.Database(DATABASE_URL, force_rollback=True)
|
|
metadata = sqlalchemy.MetaData()
|
|
|
|
|
|
class Company(ormar.Model):
|
|
class Meta:
|
|
tablename = "companies"
|
|
metadata = metadata
|
|
database = database
|
|
|
|
id: int = ormar.Integer(primary_key=True)
|
|
name: str = ormar.String(max_length=100)
|
|
founded: int = ormar.Integer(nullable=True)
|
|
|
|
|
|
class Car(ormar.Model):
|
|
class Meta:
|
|
tablename = "cars"
|
|
metadata = metadata
|
|
database = database
|
|
|
|
id: int = ormar.Integer(primary_key=True)
|
|
manufacturer = ormar.ForeignKey(Company)
|
|
name: str = ormar.String(max_length=100)
|
|
year: int = ormar.Integer(nullable=True)
|
|
gearbox_type: str = ormar.String(max_length=20, nullable=True)
|
|
gears: int = ormar.Integer(nullable=True)
|
|
aircon_type: str = ormar.String(max_length=20, nullable=True)
|
|
|
|
|
|
# build some sample data
|
|
toyota = await Company.objects.create(name="Toyota", founded=1937)
|
|
await Car.objects.create(
|
|
manufacturer=toyota,
|
|
name="Corolla",
|
|
year=2020,
|
|
gearbox_type="Manual",
|
|
gears=5,
|
|
aircon_type="Manual",
|
|
)
|
|
await Car.objects.create(
|
|
manufacturer=toyota,
|
|
name="Yaris",
|
|
year=2019,
|
|
gearbox_type="Manual",
|
|
gears=5,
|
|
aircon_type="Manual",
|
|
)
|
|
await Car.objects.create(
|
|
manufacturer=toyota,
|
|
name="Supreme",
|
|
year=2020,
|
|
gearbox_type="Auto",
|
|
gears=6,
|
|
aircon_type="Auto",
|
|
)
|
|
|
|
# select manufacturer but only name - to include related models use notation {model_name}__{column}
|
|
all_cars = (
|
|
await Car.objects.select_related("manufacturer")
|
|
.exclude_fields(
|
|
["year", "gearbox_type", "gears", "aircon_type", "company__founded"]
|
|
)
|
|
.all()
|
|
)
|
|
for car in all_cars:
|
|
# excluded columns will yield None
|
|
assert all(
|
|
getattr(car, x) is None
|
|
for x in ["year", "gearbox_type", "gears", "aircon_type"]
|
|
)
|
|
# included column on related models will be available, pk column is always included
|
|
# even if you do not include it in fields list
|
|
assert car.manufacturer.name == "Toyota"
|
|
# also in the nested related models - you cannot exclude pk - it's always auto added
|
|
assert car.manufacturer.founded is None
|
|
|
|
# fields() can be called several times, building up the columns to select
|
|
# models selected in select_related but with no columns in fields list implies all fields
|
|
all_cars = (
|
|
await Car.objects.select_related("manufacturer")
|
|
.exclude_fields("year")
|
|
.exclude_fields(["gear", "gearbox_type"])
|
|
.all()
|
|
)
|
|
# all fiels from company model are selected
|
|
assert all_cars[0].manufacturer.name == "Toyota"
|
|
assert all_cars[0].manufacturer.founded == 1937
|
|
|
|
# cannot exclude mandatory model columns - company__name in this example - note usage of dict/set this time
|
|
await Car.objects.select_related("manufacturer").exclude_fields(
|
|
[{"company": {"name"}}]
|
|
).all()
|
|
# will raise pydantic ValidationError as company.name is required
|